Chip 2000 May/Chip_2000-05_cd1.bin/zkuste/Perl/ActivePerl-5.6.0.613.msi/䆊䌷䈹䈙䏵-䞅䞆䞀㡆䞃䄦䠥/_4402434435b1673a3dbd58939af99fd0

Text File | 2000-03-15 | 1.7 KB | 78 lines

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package IO::Seekable;

=head1 NAME

IO::Seekable - supply seek based methods for I/O objects

=head1 SYNOPSIS

    use IO::Seekable;
    package IO::Something;
    @ISA = qw(IO::Seekable);

=head1 DESCRIPTION

C<IO::Seekable> does not have a constructor of its own as it is intended to
be inherited by other C<IO::Handle> based objects. It provides methods
which allow seeking of the file descriptors.

If the C functions fgetpos() and fsetpos() are available, then
C<$io-E<lt>getpos> returns an opaque value that represents the
current position of the IO::File, and C<$io-E<gt>setpos(POS)> uses
that value to return to a previously visited position.

See L<perlfunc> for complete descriptions of each of the following
supported C<IO::Seekable> methods, which are just front ends for the
corresponding built-in functions:

  $io->seek( POS, WHENCE )
  $io->sysseek( POS, WHENCE )
  $io->tell

=head1 SEE ALSO

L<perlfunc>,
L<perlop/"I/O Operators">,
L<IO::Handle>
L<IO::File>

=head1 HISTORY

Derived from FileHandle.pm by Graham Barr E<lt>[e-mail]<gt>

=cut

require 5.005_64;
use Carp;
use strict;
our($VERSION, @EXPORT, @ISA);
use IO::Handle ();
# XXX we can't get these from IO::Handle or we'll get prototype
# mismatch warnings on C<use POSIX; use IO::File;> :-(
use Fcntl qw(SEEK_SET SEEK_CUR SEEK_END);
require Exporter;

@EXPORT = qw(SEEK_SET SEEK_CUR SEEK_END);
@ISA = qw(Exporter);

$VERSION = "1.08";

sub seek {
    @_ == 3 or croak 'usage: $io->seek(POS, WHENCE)';
    seek($_[0], $_[1], $_[2]);
}

sub sysseek {
    @_ == 3 or croak 'usage: $io->sysseek(POS, WHENCE)';
    sysseek($_[0], $_[1], $_[2]);
}

sub tell {
    @_ == 1 or croak 'usage: $io->tell()';
    tell($_[0]);
}

1;